


The Baker Street Blackmailer

by EbonyKnight, RomanyWalker



Series: Greg Lestrade And The Adventure Of The Alternative Lifestyle [8]
Category: Sherlock (TV)
Genre: Blackmail, M/M, Multi, Sibling Incest
Language: English
Status: Completed
Published: 2018-04-29
Updated: 2018-04-29
Packaged: 2019-04-29 20:42:28
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,345
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/14480814
Author URL: https://archiveofourown.org/users/EbonyKnight/pseuds/EbonyKnight, https://archiveofourown.org/users/RomanyWalker/pseuds/RomanyWalker
Summary: Greg learns how his lovers got together, and it's really not what he was expecting.





	The Baker Street Blackmailer

**Author's Note:**

> Disclaimer: We do not own Sherlock. 
> 
> This is part of Greg Lestrade and the Adventure of the Alternative Lifestyle, but stands alone.

“Open your fucking eyes, you idiot! What kind of goalie are you?” Greg demanded furiously, leaning forward in Sherlock’s armchair to glare at the TV as Arsenal went three nil down to Nottingham Forest. “He’s a disgrace!”

“Hmm,” came Sherlock’s deep rumble from across the room, “his mistress made a demand for money at half time; he’s a little distracted.”

“How the hell do you know that? You’re not even watching it!” Greg turned the TV off and threw the remote down in disgust. He looked across the living room of 221b Baker Street and, despite his annoyance, felt a warm curl of something indefinable rise through him. The Holmes brothers were on the sofa, Sherlock supine with his head in Mycroft’s lap and feet dangling over the arm, and the elder brother was stroking Sherlock’s messy hair idly, both content and at ease. As new as this three-way relationship was, Greg knew that seeing them like that, relaxed and enjoying each other’s company, was something he would never tire of.

Sherlock smirked and butted his head into Mycroft’s hand demandingly. “I merely observed. You should try it; it would be advantageous is your line of work.”

“Very funny,” Greg replied, eyes on his lovers. Time spent together as a threesome was precious, and time they could have together at Baker Street even more so. With John away at a battalion reunion in Northumberland, however, Sherlock had been adamant that he wanted to spend the night with them in his own bed, and neither Greg or Mycroft had argued. Sherlock had even made an effort to tidy up, in deference to his brother’s fastidiousness; the kitchen didn’t look like a laboratory had exploded for once, and they hadn’t needed to shift piles of papers or books before they could sit down.

He watched them fondly for a long moment as Mycroft’s long, dexterous fingers carded idly through Sherlock’s curls, and the question of how their relationship had transitioned from fraternal to sexual rose in his mind again. He knew that it wasn’t really any of his business, even if he was now part of the relationship, but the curiosity was starting to eat him alive. It really wasn’t a surprise that Sherlock would so thoroughly discard societal conventions, but Mycroft was just so bloody _normal_. 

“How did this even happen?” he asked before he could talk himself out if it, waving a hand at the pair of them vaguely. 

Head still in his brother’s lap, Sherlock said, “I asked for sex and Mycroft refused, several times over the course of fourteen years. Then I pointed out that we were both adults sharing a mutual attraction and that society’s rules don’t apply to us, and he saw reason.”

Mycroft tugged on Sherlock’s hair reprovingly. "You omitted the blackmail, brother dear."

“Blackmail? Don’t be dramatic, Mycroft,” Sherlock huffed, nudging Mycroft’s hand, and Greg felt a cold weight settle sickeningly in his gut. Mycroft certainly wasn’t one for such exaggeration, but Greg couldn’t imagine even _Sherlock_ , sociopath though he was, blackmailing his brother. 

The frown Mycroft directed at the younger man had a distinct fondness about it. "You promised to stop using recreational benzodiazepines in exchange for my capitulation," he replied, massaging Sherlock’s head. "While you were in a hospital bed, recovering from a near fatal benzodiazepine overdose.”

Eyes falling closed, clearly enjoying his brother’s attention, Sherlock hummed. “I had it in my power to give you something that you wanted and offered it in exchange for something that I wanted. We made a deal. That’s subtly different to blackmail, brother mine, hospital bed or not.”

"You held your wellbeing to ransom," Mycroft replied, somehow both chastising and affectionate. "You said, as I recall, that you had every intention of stuffing yourself with all the 'pams' you could find the minute I went back to London unless I took the stick out of my arse and let you put your cock in its place."

“Yes, well, you were being unbearably stubborn. If you’d been reasonable I wouldn’t have needed to take such drastic measures,” came Sherlock’s slightly sullen reply, and Greg felt physically sick at the admission. “Anyway, you can’t complain; I stopped using benzos and you got lots of excellent sex, with a man you’d been lusting after yet denying for fourteen years, no less.” He nudged Mycroft’s hand, which had paused its petting, with his head. “Don’t stop.”

Mycroft chuckled and resumed. “I’m not complaining.”

It was then, hearing Mycroft’s obvious acceptance of Sherlock’s methods, that Greg found his voice. “Seriously?” he asked, the word dripping with disgust . “Blackmail? You blackmailed you own _brother_?”

In any other circumstances, Greg didn’t doubt that that he would have found their expressions hilarious. After all, it wasn’t often that he left either one of them looking baffled, and managing both of them simultaneously was almost something to be proud of. 

There was a long moment of silence until Mycroft asked, "Whose brother would you have preferred?"

Sherlock laughed, a real, genuine laugh, and Mycroft looked at him with poorly disguised adoration. “He was being stubborn; I needed to do _something_.” Sherlock lifted his right arm, cupping the back of Mycroft’s head to guide him down for a kiss. 

The kiss the brothers shared was lingering and tender, but Greg watched without really seeing. Thoughts were warring inside his head a he tried desperately to make sense of what he was hearing to little effect. Blackmail was _wrong_ , no two ways about it. Sherlock holding his health to ransom like that effectively took away Mycroft’s ability to tell him ‘no’, and Greg felt his anger flare anew at the thought of Sherlock using his addiction - his _life_ \- to get what he wanted and overcome his brother’s denial.

Their kiss came to an end and Greg must have been broadcasting his thoughts, because Sherlock cast a brief glance in his direction and said, “You might want to tell Greg that you don’t regret having sex with me, brother mine. He’s thirty seconds away from trying to strangle me.”

A faint crease appeared at Mycroft’s brow. "I should have thought it was patently obvious that I don't regret having sex with you,” he replied, everything about his tone and body language ringing true.

Greg watched them them, seeming for all the world like they weren’t blithely discussing blackmail and massive consent issues like they were things that happened to other people, and shook his head, appalled. “I can’t _believe_ — Do you even know what consent is, Sherlock? For fuck’s sake, you can’t _do_ shit like that!”

“I can and I did and it worked,” came Sherlock’s blunt reply, eyes fixed firmly on his brother. “He was being stubborn, refusing us both what we wanted for frankly ridiculous reasons. I merely provided a little more incentive.”

"There really were no other options available to him. I was quite determined,” Mycroft interjected reasonably, running his left thumb along Sherlock's lower lip. "And I really am rather pleased with our current arrangement."

And Greg knew that he was, had seen far too much evidence of it to think otherwise. Sherlock opened his mouth and sucked Mycroft’s thumb in with a satisfied sound, and Greg frowned. “If you’re happy with this,” he asked, gesturing between them as Sherlock did filthy things to his brother’s thumb, “and I _know_ you are, why did you keep turning him down?”

"Because he's my _little brother_ ," Mycroft replied, tone and expression making it clear that he believed that should be obvious, and perhaps it would have been to someone who didn’t know them and how little either of them respected the rules.

“No,” Sherlock mumbled around Mycroft’s thumb, before releasing the digit with a lick to the pad. “It’s because you were being tedious and wouldn’t listen to reason.”

"Or perhaps because we had a very unusual upbringing and I wasn't keen to cause you any further psychological damage. Because you're my little brother and normal siblings do not have sex with each other."

“We’re not normal siblings now and weren’t when I first propositioned you, either,” Sherlock huffed, turning his read to nose at Mycroft’s crotch. “I understand why you wouldn’t have sex with me when I was fourteen, but your obstinacy was really starting to grate when I hit my twenties.”

"It had become a point of principle by then."

“But that’s all in the past,” Sherlock murmured into the fabric of Mycroft’s trousers and slipped a hand under his waistcoat. Greg watched its progress, feeling his body reacting despite the legion of unanswered questions marching around his head. 

Mycroft chuckled, the sound both fond and amused. "It certainly is."

“Would you have changed your mind if he wasn’t a blackmailing bastard?” Greg asked, not at all sure that he wanted the answer.

"No,” was Mycroft’s simple response, his expression tender as he watched Sherlock shift on the sofa until he could get Mycroft’s trousers open.

Frowning slightly as he watched the younger Holmes mouth at Mycroft’s cock through his underwear, Greg did his best to pull his scattered thoughts together. “You get that that sounds like seriously dubious consent to me, yeah?”

Long fingers buried themselves in Sherlock’s hair again and Mycroft laughed. “It isn’t like I didn’t want to.”

“He also wanted a reduction in my drug use,” Sherlock interjected, voice slightly muffled. “Really, Mycroft wasn’t the only one of us played. Being told that I could have him once I’d stayed clean of benzodiazepines for a month, and that the arrangement would last for only as long as I abstained, worked when nothing else had, as he knew it would. I’ve not used them since because it wasn’t worth losing this.”

Several long moments passed as Greg let that sink in. He watched without really seeing as Sherlock extracted his brother’s cock from his trousers and took it into his mouth. Heard Mycroft’s soft sound of pleasure without registering it. He’d long since known that Sherlock was a ruthless bastard, that there was little that he wouldn’t do to achieve his aim, but blackmailing his brother into sex? Not that Mycroft seemed to mind, of course, if the way he was responding to Sherlock’ ministrations was reliable indicator. If anything, he seemed almost _proud_ of Sherlock’s ruthlessness, and Greg knew for a fact that he was happy with their current situation. The way he relaxed imperceptibly when Sherlock was around, even in a foul mood, made that much evident. In the short time that they’d been together as a threesome, he’d seen the same from Sherlock; he was so much more settled, less fractious, after time with his brother, time when they didn’t need to put on a façade and could simply be themselves. 

At length, Greg lifted his gaze from where it had settled on Mycroft’s lap and scratched his jaw, the rasping of stubble loud in his ears. “I’ll never understand the pair of you,” he declared, looking Mycroft in the eye. 

Mycroft extended the hand that wasn’t buried in his brother’s hair, inviting Greg to join them. "Do you need to? Or can you enjoy watching my brother fellate me nonetheless?" Only an ever so slight change in tone give away that Sherlock’s attentions were having any effect at all.

“No, I don’t; it works for the pair of you so it works for me,” Greg replied after a brief hesitation. Sherlock was a blackmailing bastard who’d effectively used his life to bed his brother. But his brother was as, if not more, ruthless and would not have done anything he didn’t want to. That settled in his mind, even if it didn’t sit entirely comfortably, he crossed the room to sit on the arm of the sofa and kissed the elder Holmes. “I can always enjoy watching this mouthy little sod blow you.” 

"I imagine he'll want to attend to you once he's finished with me." 

Sherlock hummed happily in assent, the resultant sensation drawing a quiet sound of pleasure from Mycroft. Greg watched as his cheeks hollowed, lips stretched obscenely around Mycroft’s cock, and felt his own harden. “Fuck, I could watch this all day,” he said, reaching down to thread his fingers into Sherlock’s hair. The younger man had very sensitive follicles, and Greg wasn’t above using that in the pursuit of pleasure. He gave a non-too gentle tug and Sherlock whined, groping himself with one hand and upping the ante with his mouth. 

Beside him, Greg noted Mycroft’s breathing accelerating and the fingers twined with his tightened their grip, sure signs that he was approaching orgasm. There was something about seeing Mycroft, usually so pristine and in control, in a state of dishevelment and at the mercy of his body’s responses that made Greg’s his skin feel two sizes too small. When he was in that state because of Sherlock, who was never anything less than breathtaking, it was almost enough to leave him dizzy.

Sherlock was nothing if not a perceptive lover, and he responded instantly when Mycroft’s breathing hitched; he pulled his mouth up the shaft, cheeks hollowing, and then focussed his attention on the head, bringing his free hand into play to work the shaft. Greg felt his cock throb, trousers suddenly much too tight for comfort, when the elder brother’s head fell back, flushed neck arching beautifully as he came. 

“God, you two…fucking incredible together,” Greg murmured, eyes flicking between Mycroft, face flushed and breathing heavily, and Sherlock, hair wild from being played with and now directing a smug yet lascivious smile his way. 

“Hmm, we are” Sherlock agreed and licked his lips. “Mycroft is a very attractive man and you’ve always fancied me, even if you didn’t want to acknowledge it.” He shifted, moving fluidly up onto his knees, putting one hand on Mycroft’s shoulder for balance and reaching for Greg’s tie with the other. He gave it a firm tug, pulling Greg close enough that they could kiss over Mycroft’s head. “Now, Detective Inspector, I do believe that it’s your turn.”


End file.
